export declare const isWhiteSpaceOnly: (s: string) => boolean;
export declare const findFirstImageSrc: (html: string) => string;
/**
 * Split string, preserving specific newline used for each line
 */
export declare function splitSpecial(s: string): {
    text: string;
    newLineChar: '\r' | '\n' | '\r\n' | '';
}[];
/**
 * Surround tag content with delimiter (moving any leading/trailing space to outside the tag
 */
export declare function tagSurround(content: string, surroundStr: string): string;